Beezermacc is quite right.
We say on our site that Initial fitment does, however, involve disabling or removing the old condenser/capacitor. This is a delicate but not particularly difficult task, which we explain in very great detail.
Those were my words back when we started, and I stand by them. It IS delicate, but for people who happily tear gearboxes apart and put engines together and make all sorts of parts for themselves etc etc, I didn't and still don't think the hands-on owner should find it too difficult.
But, because it certainly isn't easy, we go to what some people think are ridiculous lengths to explain what has to be done, to the extent of teaching grannies to suck eggs.
The K2F is the easiest common armature to attack, provided the coil is good of course, because it is possible to disable the old condenser simply by snipping and insulating the low tension live + "link" wire at the condenser end. They are usually accessible, except in some cases where the wires are very short (on rewinds often) and the condenser connections for a modern replacement are buried in resin that is hard to dig out without breaking anything.
Most people who have wanted to do it have done it just fine, including many people on this forum.
The most difficult EasyCap application is for the low inertia steel cb assembly, for which the EasyCap board is a dainty bit of kit designed for two very small capacitors on its wings. The biggest problem owners encounter is the length of the spring blade tail screw on these steel cb assemblies - It mustn't be long enough to touch the 'wrong' metallised side of the circuit board. Cutting/filing down a 6BA screw is a painful job as well - my workshop floor would reveal a few of the darn things that got away.
The second most common problem (not limited to EasyCap installation either!) is fitting the cb with the spring blade kissing the camring - which is fatal on the steel assembly owing to the fact the moving point is 'low tension live'. It's 'earth' on the earlier brass sort, so a kiss won't matter. It will just wear out the spring until it might even break.
It would be ridiculous to claim that anything like this won't ever fail, because of course one will, sometime or another.
However, of over 5000 sold we have had 3 or maybe 4 back. One blew on Day 1 (manufacturing defect, or us getting too enthusiastic with the soldering iron); a second didn't work on the customer machine (magdyno) when another one he fitted did - but I use the first one as a test piece often and it does work fine; and a third had been somewhat manhandled. They're all guaranteed 2 years and I'll always send one out to anyone with doubts, or who wants to test by simple substitution.
I carry a spare on a keyring, but in an aggregate 50K miles probably, on my 'mule' A10 and 2 AMC twins over 4 years, all weathers, I haven't had a problem. I take them off regularly to test them, to see that the capacitance remains within the 10% limit of spec, and that they remain leak-proof to 2 Giga Ohms at 500v. They always have. I admittedly have the advantage that I know the rest of each magneto on which they are fitted is in tip-top shape, but even so, they have already done better than 2 reconditioned armatures that were on 2 of the machines, whose condensers broke down at under 10,000 miles. The motivation for our product was the premature failure of a rebuilt mag on my A, and of the similarly-rebuilt magneto on one of the late KenF's bikes: we reckoned that if things HAD to go wrong, then let them please go wrong in a place you can get at them. The premature failures both involved the use of one particular brand of commonly-used condenser. We can't, and I wouldn't, condemn anything out of hand - but I know what I avoid, and I have dug out many dozens of them which have suffered the fate of my A and KenF's Rapide.
The problem is that you don't always know what you are getting, as there are very few trade winders out there, and many suppliers use the same few sources' choice of buried condenser. Nor can 99% of people be expected to be able to tell the differences - until after they break down, in a howling gale and pissing rain, as I did.
Anyone with a cheapish high voltage leak tester can test an EasyCap, and anyone with a simple multimeter with a capacitance scale can test its capacitance. 150nF for the brass cb, 136nF for the steel. Whenever installing one, I ALWAYS hold the cb open on the bench after fitting the board, and measure from backplate to live point - that should show the capacitance. If it just shows 'ohms' and probably squeals at you, then the fitment has gone wrong. This is not a game you can easily play with a buried item not disconnectable from the low tension winding.
Very happy to discuss any particular problems via PM or email, rather than behave like a pernicious vendor here!
Cheers, Bill (with my Brightspark hat on)
